subsys: random: Fix semaphore initial count of xoroshiro128

Semaphore state_sem initial count is set to 0 but k_sem_give()
is invoked first in sys_rand32_get() which will block the caller
forever.

Fix the issue by setting the initail count to count_limit.

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>